Combination flash eliminator and stabilizer for a firearm



. A. HAMMER 2,792,760 COMBINATION FLASH ELIMINATOR AND STABILIZER FOR AFIREARM May 21, 1957 Filed March 26, 1954 INVENTOR. Alexunfle r Humm ETA TTOR NE Y5 COMBINATION FLASH ELIMINATOR AND STABELIZER FOR A FIREARMAlexander Hammer, Springfield, Mass., assignor to the United States ofAmerica as represented by the Secretary of the Army Application March26, 1954, Serial No. 419,117

6 Claims. (Cl. 89-14) (Granted under Title 35, U. S. Code (1952), sec.266) The invention described herein may be manufactured and'used by orfor the Government for governmental purposes without the payment of anyroyalty thereon.

This invention relates to muzzle attachments for firearm barrels and ismore particularly directed to a combined flash eliminator, silencer andstabilizer.

In the design of military weapons, considerable efforts have beenexpended in various attempts to eliminate the smoke and flash normallypresent at the muzzle end of the barrels during automatic fire. Whilethe problem of smoke accumulation has been virtually eliminated by theuse of modern types of smokeless powders, the prior art has not met withthe same degree of success in the concealment or elimination of flashduring relatively long bursts of sustained fire. Although numerousattempts have been made to eliminate flash by providing means forcooling the muzzle end of the barrel to a temperature substantiallybelow the ignition point of the unburnt particles of powder whichcustomarily accompany the gases evolved upon the discharge of eachcartridge, it has invariably been found impossible to provide therequisite drop in temperature over the relatively short length of thecustomary muzzle attachment. Accordingly, present attempts at reducingthe flash have been directed toward breaking up the shock waves producedby the discharge gases immediately upon emergence thereof from themuzzle of the firearm barrel. While this approach to the problem has metwith far greater success than the flash hiders previously employed intheart, elimination of all of the flash during sustained fire has not asyet been achieved because the temperatures at the muzzle end of thebarrel remain above the ignition point of the unburnst powder particles.

Accordingly, it is an object of this invention to provide an improveddevice for attachment to the muzzle end of afirearm barrel which willeffectively cool the discharge gases passing therethrough to atemperature below the flash point of the powder utilized in theparticular ammunition employed.

It is a further object of this invention to provide a muzzle attachmentof the aforesaid type capable of imparting a vortex flow to thedischarge gases passing therethrough while simultaneously diluting suchgases with air from the atmosphere.

Still another object of the present invention lies in providing animproved device for attachment to the muzzle end of a firearm barrelwhich will effectively disperse the shock waves created by the passageofthe dis charge gases through the barrel. 7

Another object of this invention is to incorporate in a flash eliminatorfor attachment to the muzzle end of a firearm barrel the dual functionsof substantially reducing the temperature of the discharge gases passingtherethrough and of dispersing the shock waves created by the passage ofthe gases through the barrel.

f It is a specific object of. this invention to'provide a simple yetefl'icient flash eleminatorof the aforesaid type.

, 2,792,760 Patented M-ay -2i1-, 1957 which will also act as astabilizer, a recoilvcheck, and a silencer without the necessity forfurther adjustment or any replacement of parts.

The specific nature of the invention as well as other objects andadvantages thereof will clearly appear from a description of a preferredembodiment as shown in the accompanying drawings in which:

Fig. 1 is an exploded perspective view of the muzzle attachment of thepresent invention;

Fig. 2 is a rear end view of the spiral vane mounted in the conicalnozzle;

Fig. 3 is a longitudinal cross-section of the attachment mounted to themuzzle end of a firearm barrel;

Fig. 4 is a rear end view of the muzzle attachment showing the openingsby which atmospheric air is sucked therethrough; and

Fig. 5 is a fragmentary view of an alternate form for the front end ofthe muzzle attachment.

As illustrated in the drawings, the flash eliminator of the presentinvention essentially comprises a forwardly converging conical nozzle 12and a spiral Vane 13 fitted therein. The rear end of nozzle 12 isprovided with a cylindrical portion 14 in which a mounting bracket 15 issecured by any suitable means such as screws 16. Bracket 15 is providedwith an interiorly threaded hub portion 17 engageable with a matingthreaded portion at the muzzle end of a firearm barrel 18. Extendingradially outward from hub portion 17 are a plurality of webbed spokes 19each terminating in an arcuate flange 2% adapted to mate with theinterior periphery of cylindrical portion 14 of nozzle 12. Suitablethreaded holes 21 are provided in flanges 20 to receive screws 16 uponpassage thereof through suitable holes 27 in cylindrical nozzle portion14. Vane 13 is preferably formed from a ribbonlike strip of metalspirally wound to fit snugly within the forwardly tapering interior ofnozzle 12 and is adapted to be retained therein by contact with thefront face of mounting bracket 15. The number of turns of spiral vane 13depend, of course, upon the size of nozzle 12 and the extent to whichthe discharge gases must be cooled. Although vane 13 is shown in thedrawings with a clockwise spiral, it should be understood that thedirection in which the surface is spiraled can be counterclockwise asWell. In any event, the spiral configuration of vane 13 forms alongitudinal cylindrical hole 22 through nozzle 12 of slightly greaterdiameter than the bore of barrel 18 and in axial alignment therewith.The spaces between spokes 19 define openings 23 as best shown in Fig. 4leading into the interior of nozzle 12 for a purpose to be hereinafterdescribed.

During automatic fire, the discharge gases evolved upon the explosion ofthe cartridges pass through barrel 18 and upon issuance from the muzzleend thereof expand in the larger volume afforded by the interior ofnozzle 12 and thereby impinge with substantial force upon the rearmostsurfaces of vane 13. As a result of the path of movement imparted to theforwardly moving high velocity gases by the spiral configuration of vane13, such path being hereinafter referred to as vortex flow, the hotgases which are traveling adjacent to and through axial hole 22 tend toslow down while those gases traveling adjacent to the interior Wallsurface of nozzle 12 tend to speed up. The frictional contact effectedby the difierences in the rotational velocity of adjacent layers of thedischarge gases increase thetemperature thereof to an appreciablygreater extent at the outer peripheries of the vortex flow than at theinner core thereof so that the faster moving gases adjacent the wallsurfaces of nozzle 12 absorb heat from the slower moving gases as theytravel through hole 22; l Sincethehotdischarge gasesare subje'ctedto.this 'refrigerating'eft'ect' along the entire length of nozzle 12, thedecrease in temperature between the rear and front ends thereof is of anappreciable extent.

At the same time, the high velocity forward movement of the dischargegases along the sinuoussurfaces of spiral vane 13 creates a suctioneffect which draws in air from outside of barrel 18 through the openings23 between spokes 19 of mounting bracket 15. In continuous automaticfire, this suction effect is sufiicient to cause the atmospheric air tojoin in the vortex flow of the discharge gases and effect an appreciabledilution thereof. The considerably lower temperature of the air beingsucked in tends to further cool the discharge gases passing through hole22 in addition to prevent excessiveheating of the wall surfaces ofnozzle 12. As a result of the refrigerating effect of the vortex flowand the cooling effect of the atmospheric air, the temperature gradientbetween the muzzle end of barrel 18 and the front end of nozzle 12amounts to as much as which, in the majority of firearms, is sufficientto reduce the temperature below the ignition point of the unburntparticles of powder.

The amount of atmospheric air sucked into openings 23 at the rear end ofnozzle 12 can be considerably increased by extending the conicallyconverging front end walls thereof to form a conically diverging portionas best shown at 24 in Fig. 5. This is accomplished as a result of theadditional vacuum effect produced by the controlled expansion of thedischarge gases upon exit from hole 22 and entry into diverging portion24 of nozzle 12.

Moreover, it is well known that the shock waves which accompany thedischarge gases duringv their passage through barrel 18 contributesubstantially to the amount of flash which customarily appears at themuzzle end thereof. Accordingly, the configuration of vane 13 has beendesigned to provide an effective means of breaking up these shock waveswhile the discharge gases are forced into the aforementioned vortexflow. This is essentially due to the fact that the sinuous surfaces ofspiral vane 13 change direction simultaneously in three dimensions andtherefore disperse the shock waves by reflecting each fragmentaryportion thereof in a different path.

Another beneficial result produced by the aforementioned.

dispersion of the shock waves is the substantial reduction of the loudreport customarily created by the inevitable expansion thereof upon exitfrom the muzzle end of the barrel or any device attached thereto.

It is also aparent that the forward thrust of the high velocitydischarge gases on the surfaces of vane 13 and the conical wall surfacesof nozzle 12 is counter to the recoil thrust of the firearm. In fact,experiments have shown that this opposing thrust of the attachmentprovides as much as a 50% decrease in the recoil energy of the firearmduring continuous fire. In addition, this forward thrust of thedischarge gases can be employed to substantially counteract the tendencyof the muzzle end of the barrel to climb upwardly during sustained fireas the entire firearm pivots about the operators shoulder as a fulcrum.This can be readily accomplished by drilling suitable bleeder ports 25in the walls 'ofnozzle 12 in. the locations best adapted to dissipatethe undesirable outward thrust of the discharge gases. The lateral whipnormally imparted to the muzzle end of the barrel as a result of thetorque created by the passage of the bullets through the helical riflingtherein can be similarly reduced by compensating bleedcr ports 26. Inthis respect, it will be noted that where vane 13 is spiraled in acounterclockwise'direction, the vortex flow imparted to the dischargegases aids substantially in reducing the lateraltwhip of the firearmbarrel. If desired a plurality of holes 25 and 26 can be drilled throughthe walls of nozzle 12 and then suitably plugged to leave. open onlythose required to compensate for the vertical and lateral move-.

4. ments imparted to the barrel of the particular firearm on which theattachment of the present invention is em'-' ployed. If the attachmentis changed to another firearm, holes 25 and 26 may be plugged orunplugged in accordance with the relative changes in the firingcharacteristics thereof.

Accordingly, there is here provided an eflicient, sturdy attachment forthe muzzle end of firearm barrels which although constructed of but twomajor parts isadapted not only to suppress and eliminate the visibleflash normally existing during continuous fire but to act as a silencer,recoil check, and stabilizer as well.

Although a particular embodiment of the invention has been described indetail herein, it is evident that many variations may be devised withinthe spirit and scope thereof and the following claims are intended toinclude such variations.

I claim:

1. A flash eliminator for a firearm barrel comprising a forwardlyconverging hollow conical nozzle, bracket means for securing said nozzleto the muzzle end of the barrel, spiral means within said conical nozzlefor imparting a refrigerating. vortex flow to the discharge gasesissuing from the barrel, and passage means in the rear end of saidconical nozzle for admitting atmospheric air into the interior thereofin response to the vacuum created by the vortex flow for further coolingthe discharge gases passing therethrough in addition to the interiorwall surfaces of said nozzle and said spiral means.

2. A flash eliminator for a firearm barrel comprising a forwardlyconverging hollow conical nozzle, bracket means in the rear end of saidnozzle for mounting said nozzleto the muzzle end of the barrel, spiralmeans within said conical nozzle, having a sinuous surface for impartinga refrigerating vortex flow to the discharge gases issuing from thebarrel and for simultaneously breaking up the shock waves formed by thegases during passage through the barrel, said sinuous surface beingarranged to limit the hollow interior of said nozzle to an axialcylindrical bore, and passage means in the rear end of said nozzle foradmitting'atmospheric air therein in response to the vacuum created bythe vortex flow.

3. A flash eliminator for a firearm barrel comprising a forwardlyconverging hollow conical nozzle having an exit at the smaller endthereof of greater diameter than the bore of the barrel, and arectangular strip spirally wound within the interior of said nozzle toform a cylindrical bore therethrough in axial alignment with the bore ofthe barrel.

4. A flash eliminator for a firearm barrel comprising a forwardlyconverging hollow conical nozzle terminating at the smaller end thereofin a diverging conical portion, bracket means fixedly secured in therear end of said nozzle for attachment thereof to the muzzle end of thebarrel, spiral means in said nozzle terminating at the origin of saiddiverging front end portion thereof, said spiral means having a sinuoussurface for imparting a refrigerating vortex flow to the discharge gasesissuing from the barrel and for simultaneously breaking up the shockwaves formed by the gases during passage through the barrel, saidsinuous surface cooperating with the converging walls of said nozzle toform :a cylindrical bore therethrough in axial alignement with the boreof the barrel, said bracket means having passages therethrough foradmitting atmospheric air into said nozzle and against said sinuoussurface of said spiral means in response to the vacuum createdby thevortex flow and the expansion of the discharge gases upon entry into thelarger volume afiorded by said diverging conical portion at the frontend of said nozzle.

5. A combination flash eliminator, recoil check, and stabilizer for afirearm barrel comprising a forwardly converging hollow-conica-l nozzleterminating at the smaller end, thereof in an opening substantiallyequivalent in diameter to the bore of the barrel, a bracket secured inthe rear end of said nozzle and having a threaded hub portion formounting said nozzle to the muzzle end of the barrel, a spiral membercooperating with said nozzle to form an axial cylindrical boretherethrough in longitudinal alignment with the bore of the barrel andof slightly greater diameter relative thereto, said spiral memher havinga sinuous surface for imparting a refrigerating vortex flow to the highvelocity discharge gases issuing from the barrel and thereby reducingthe temperatures thereof below the ignition point of the powder in theammunition employed, said sinuous surface cooperating with the conicalwalls of said nozzle to receive the forward thrust of the dischargegases thereon for reducing the recoil energy of the firearm, saidconical nozzle having a plurality of ports therein located so as tobleed the discharge gases therefrom in a direction opposite the upwardlift and lateral whip imparted to the muzzle end of the firearm barrelfor producing a stabilizing elfect thereon during continuous fire.

6. A combination flash eliminator and silencer for a firearm barrelcomprising a forwardly converging hollow conical nozzle terminating atthe smaller end thereof in an opening substantially equivalent indiameter to the bore of the barrel, a mounting bracket secured in therear end of said nozzle and having a threaded hub portion and aplurality of radial spokes extending outwardly therefrom, means on saidhub portion for mounting said nozzle to the muzzle end of the barrel, aspiral member cooperating with said nozzle to form an axial cylindricalbore therethrough in longitudinal alignment with the bore of the barreland of slightly greater diameter relative thereto, said spiral memberhaving a sinuous surface exposed to the high velocity gases issuing fromthe barrel to impart a vortex flow thereto for effecting cooling of thecentral inner portion of the spiraling mass of gases, said sinuoussurface cooperating with the conical walls of said nozzle to reflect theshock waves formed by the discharge gases during the passage thereofthrough the bore of the barrel whereby the resulting dispersal thereofeliminates the flash and noise which accompanies continuous fire, saidspokes on said hub portion defining passages therebetween for admittingatmospheric air against said sinuous surface in response to the suctioncreated by the vortex flow for cooling the outer portion of thespiraling gases and the interior Wall surfaces of said nozzle to assistin reducing the temperature of the discharge gases below the flash pointof the powder utilized in the ammunition employed.

References Cited in the file of this patent UNITED STATES PATENTS1,341,363 Fiala May 25, 1920 1,605,393 Cutts Nov. 2, 1926 1,667,186Bluehdorn Apr. 24, 1928 FOREIGN PATENTS 125,158 Great Britain Apr. 17,1919

